1. Field of the Invention
The present invention relates to an image forming apparatus and an image forming method.
2. Description of the Related Art
A recording medium for offset printing (hereinafter referred to as offset coat paper) including a support mainly made of cellulosic fiber and a coating layer applied onto at least one surface of the support is cheaper than a recording medium for inkjet printing. Therefore, the offset coat paper is demanded to be applied to inkjet image forming technology.
However, in the case where a conventional aqueous ink for inkjet printing is applied onto a sheet of the offset coat paper, the ink is not absorbed into the sheet and is spread over a surface of the sheet, resulting in failure called as beading. The beading is a phenomenon in which adjacent dots having to be discrete coalesce together.
In order to improve the beading, there has been known technology for increasing hydrophilicity of a recording medium through plasma pretreatment thereof to thereby improve permeability of an ink (Japanese Patent Application Laid-Open (JP-A) No. 2009-279796).
Meanwhile, for the purpose of improving image quality, an ink containing an anionic self-emulsifying polyurethane resin particle has been known (JP-A No. 2009-173805 (Japanese Patent (JP-B) No. 5196235)).
JP-A No. 2013-139524 discloses an ink containing a compound selected from the group consisting of methoxy propionic amide, butoxy propionic amide, dioxolane alcohol, and oxetane alcohol.
JP-A No. 2012-107210 proposes an ink which contains a water-soluble organic solvent consisting of an amide compound.